This invention relates to cartridge based data storage systems. More particularly, the invention relates to head load ramps for a removable media disk drive.
Cartridge based tape and disk data storage devices for storing digital electronic information have been in use in the computer industry for several decades. Removable disk cartridges typically comprise an outer casing or shell that houses a disk-shaped magnetic, magneto-optical or optical storage medium upon which information can be stored. The cartridge shell often comprises upper and lower halves that are formed of injection molded plastic and are joined together to house the disk. Magnetic disk media can be either rigid or flexible and are mounted on a hub that rotates freely within the cartridge. When the cartridge is inserted into a disk drive, a spindle motor in the drive engages the disk hub in order to rotate the disk within the cartridge at a given speed. The outer shell of the cartridge typically has a media access opening proximate one edge to provide the recording heads of the drive with access to the disk. A shutter or door mechanism is provided to cover the head access opening when the cartridge is not in use to prevent dust or other contaminants from entering the cartridge and settling on the recording surface of the disk. The shutter is commonly biased to a closed position with a spring bias. To open the shutter and gain access to the media, the drive employs a mechanism that overcomes the bias of the spring.
Disk drives for use with such removable disk cartridges typically employ either a linear actuator mechanism or a radial arm actuator mechanism for positioning the read/write head(s) of the disk drive on the recording surface(s) of the storage medium, or disk. Because the disk cartridges are designed to be removable from the drive, the linear or radial arm actuators must be able to move off, and away from, the storage medium to a retracted position in order to prevent damage to the head(s) when a cartridge is inserted and removed from the disk drive. Moreover, many removable cartridge disk drives employ a pair of opposing read/write heads for recording and reproducing information on both sides of a storage medium. Typically, the opposing heads are disposed on flexible suspension arms at the distal end of an actuator that allow the heads to fly closely over the respective surfaces of the rotating disk. The opposing heads must be spread apart as they approach the edge of the disk during a head loading operation in order to avoid collision with the edge of the disk. Similarly, when the heads are unloaded from the disk, they must again be spread apart to avoid collision with the edge of the disk and each other.
Prior art removable media disk drive mechanism employed load ramps to safely unload the head from the media during cartridge insertion and ejection. Typically, such load ramps move over the edge of the media and capture the heads during cartridge ejection. After capturing the heads, the heads and the load ramp move in tandem away from the edge of the media. During cartridge insertion, these load ramps move back over the edge of the media in tandem with the heads after the media is fully mounted in the drive. Thereafter, the heads are permitted to unload onto the media surface. In this way, the load ramp protects the heads and the media from damage that could result if the heads collided with the edge of the media. However, where it is desirable to make a disk drive as small as possible, surface area of the drive becomes a premium commodity.
The existing load ramp designs pivot in the same plane as the media toward and away from its edge. This movement of the load ramp requires additional space on the drive chassis to accommodate the movement of the head ramps. Thus, a head load ramp that overcomes the drawbacks of the prior art is desirable. The current invention is directed to providing such a load ramp.